Major goals for the next year follow: a) To continue studies on the electrolyte physiology of the lens, with particular respect to the role of bicarbonate ion and carbonic anhydrase. b) To explore the use of carbonic inhibitors in lowering intraocular pressure by topical application to the cornea. We already have leads that suggest quite clearly what type of physico-chemical properties will give the desired effect. This requires a concerted effort in organic chemistry, enzymology, and ocular physiology. c) The following drugs will be examined for their effect on ion entry from plasma to CSF; ouabain, SITS, spironolactone, triamterene. This should reveal whether the linking of sodium to Cl- and HCO3- passage is similar (for these drugs) to what we have found for acetazolamide, and thus reveal an important facet of their underlying mechanisms.